caa a22 4500 465826482 CHVBK 20180323112150.0 cr unu---uuuuu 170327e19900801xx s 000 0 eng 10.1007/BF00302595 doi (NATIONALLICENCE)springer-10.1007/BF00302595 Metabolism of inositol 1,4,5-trisphosphate in squid photoreceptors [Elektronische Daten] [Susan Wood, Ete Szuts, Alan Fein] Summary: Inositol 1,4,5-trisphosphate (InsP3) is rapidly formed in squid photoreceptors in response to light, where it is converted sequenctially into inositol bisphosphate (InsP2) and inositol monophosphate (InsP1). All of the InsP3 appears to be degraded to inositol 1,4-bisphosphate via an InsP3-phosphatase, which is characterized in this study. The enzyme is water-soluble and present in the light-transducing distal segments of squid photoreceptors. It has a Km of 50 μM for InsP3, requires Mg++ for its activity, is maximally active at neutral pH, specifically hydrolyses the 5-phosphate and is inhibited by 2,3-diphosphoglycerate. In these respects, InsP3-phosphatase of squid is very similar to the enzymes of other cells. Since no InsP4 or more highly phosphorylated inositols are found in squid photoreceptors, the InsP3-phosphatase may be important in the regulation of InsP3 concentration within these cells. Springer-Verlag, 1990 InsP3-phosphatase nationallicence Photoreceptors nationallicence Squid nationallicence Inositol phosphates nationallicence Inositol trisphosphate nationallicence InsP 1 , InsP 2 , InsP 3 , InsP 4 , InsP 6 : inositol monobis-, tris-, tetrakis-, hexakisphosphate, respectively nationallicence 2,3-DPG : 2,3-diphosphoglycerate nationallicence EDTA : ethylene diamine tetraacetic acid nationallicence DTT : dithiothreitol nationallicence Hepes : 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid nationallicence PMSF : phenylmethylsulfonyl fluoride nationallicence Wood Susan Boston University Marine Program, 02543, Woods Hole, MA aut Szuts Ete Department of Physiology, Boston University School of Medicine, 02118, Boston, MA, USA aut Fein Alan Department of Physiology, University of Connecticut Health Center, 06032, Farmington, CT, USA aut Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 293-298 0174-1578 160:3<293 1990 160 360 https://doi.org/10.1007/BF00302595 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00302595 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wood Susan Boston University Marine Program, 02543, Woods Hole, MA aut NATIONALLICENCE 700 1- Szuts Ete Department of Physiology, Boston University School of Medicine, 02118, Boston, MA, USA aut NATIONALLICENCE 700 1- Fein Alan Department of Physiology, University of Connecticut Health Center, 06032, Farmington, CT, USA aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer-Verlag 160/3(1990-08-01), 293-298 0174-1578 160:3<293 1990 160 360 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer